Spain–United Kingdom border

What Utrecht handed over

British forces captured Gibraltar during the War of the Spanish Succession, and Spain formally ceded it in 1713.^[1] Article X of the Treaty of Utrecht gave Britain the town, castle, port and fortifications, but “without any territorial jurisdiction”, and cut off open communication by land with the surrounding country.^[2]

Spain reads the treaty as ceding only what it names, and so not the isthmus, the low sandy strip about 1.6 km long that joins the Rock to the mainland. Britain argues that because the cession was meant to be permanent, Gibraltar also has territorial waters, though the treaty doesn’t mention them.^[3][1] In 1908–09 the UK put up a fence across the isthmus, setting the border there on its own.^[3]

“…the above‑named propriety be yielded to Great Britain without any territorial jurisdiction, and without any open communication by land with the country round about.”^[2]

An airport on the isthmus

Britain built Gibraltar’s airport on the isthmus during World War II, so it lies on the land Spain disputes. In 2006 the two countries agreed to share the facility, but the arguments didn’t stop: in 2014 Spain kept Gibraltar out of the EU’s Single European Sky scheme until the sovereignty question is settled.^[3]

Closed, opened, queued

Spanish restrictions on crossing grew through the 1950s and 1960s, and on 8 June 1969 General Franco’s government closed the gates altogether. They stayed shut after Franco died in 1975. Once Spain applied to join the European Economic Community, a closed border between two parts of it became unthinkable: the crossing reopened to pedestrians in 1982 and fully, to vehicles, in 1985. Gibraltar’s government calls the closure a policy of coercion.^[4]

Tensions returned in 2013, when Gibraltar dropped 72 concrete blocks into the sea to make an artificial reef and Spain responded by tightening checks at the border.^[3]

After Brexit

Gibraltar was left out of the UK–EU trade deal after Brexit, raising the prospect of a hard border for the 15,000 people, more than half of Gibraltar’s workforce, who cross each day. The EU and UK signed a treaty in Brussels, and from 15 July 2026 people no longer face a physical border there.^[5]

Gibraltar’s residents can now enter Spain with residence cards, and Spanish citizens can enter Gibraltar with an ID card. Checks for the Schengen area have moved to Gibraltar’s port and airport, carried out by British and Spanish officers side by side. The treaty leaves British sovereignty untouched.^[5]